Whirlpool Galaxy (M51)

Grand-design spiral galaxy interacting with its dwarf companion NGC 5195, showcasing textbook spiral arm structure.

Core Principles & Analysis

• Lord Rosse sketched its spiral structure in 1845 with his giant reflector, the first spiral form ever seen in a 'nebula'.
• Gravitational interaction with its companion NGC 5195 compresses gas and drives vigorous star formation along its arms.
• It produced three observed supernovae within two decades: 1994I, 2005cs, and 2011dh.

Specifications & Metrics

• GALAXY TYPE: Grand-design Spiral (SA(s)bc)
• DISTANCE: 23.5 million light-years
• DIAMETER: ~76,900 light-years